Traditional aesthetic surgical approaches to excess collections of adipose tissue have involved open surgical excision of the fat and overlying skin in the affected region. Such dermolipectomy was effective but had significant recovery time and placed a visible scar, often of substantial size, at the surgical site.
More recently, suction-assisted lipectomy has been used. In this technique, a thin cannula of metal or plastic or composite material is advanced along the area of fat collection through a small stab incision (5-10 mm) in the skin. This cannula is passed back and forth to traverse the entire area of fat in which reduction is desired. Often this will be done from more than one access incision surrounding the same area to provide a different angle for the passes with the cannula. During the insertion and removal of the cannula, suction is applied through the lumen of the cannula. This allows fat to be drawn in through the openings in the tip of the cannula which then breaks fat globules off by virtue of the suction action or by motion of the cannula hole edges against the fat or both or other actions. Additional fat is damaged by the suction or bruising or cutting action of the cannula which produces cell death or necrosis of fat in situ in addition to that fat which is physically removed thorough the cannula. This controlled in situ tissue injury adds to the contour improvement by providing additional loss of fat and may aid in skin contraction/scarring.
Further improvements have taken place in adjunctive techniques for suction-assisted lipectomy. These include use of the “tumescent technique.” This technique involves the infusion of large amounts of a very dilute anesthetic/vasoconstrictor solution into the tissues prior to use of the suction cannula. This is thought to increase the rate and completeness of fat removal, decrease blood loss, and postoperative bruising and recovery time. In addition, anesthesia following this wide infiltration of the solution is protracted. The volume of fluid added reduces the need for large amounts of intravenous infusion and allows larger volumes of fat to be suctioned due to the reduced blood loss.
Cannulas have been developed which incorporate additional features besides openings at the tip to allow application of suction. Cannulas which have ultrasonic generators at the tip are believed to be under development. These cannulas are thought to allow increased fat removal due to disruption of fat cells by the sound waves produced by the ultrasonic element in the tip. The energy used is applied or transmitted external the cannula into the fat surrounding the cannula tip (See Zocchi M C: Ultrasonic assisted lipoplasty: Technical refinement and clinical evaluations; Clinics in Plastic Surgery (203(4): 575-598, 1996). The sound producing element is stated to produce a smoother skin contour due to more even removal of fat cells. The technique is slow requiring much more time than traditional suction alone techniques. The tip tends to become hot creating a risk of burning the skin.
Laser devices have been tested for suction-assisted lipectomy, (see Apfelberg D B: Results of a multicenter study of laser-assisted liposuction, Clinics in Plastic Surgery 23(4): 713-720, 1996). These laser devices fire a laser fiber just proximal to the opening in the cannula across the space just deep to the opening in the cannula. This design appears to fire the laser in the fat that is about to be drawn into the opening in the cannula, such as a single hole device. While some contact may take place between the laser fiber and the fatty tissue, the system appears to be designed for delivery of light energy to the fat without direct contact with the fat being required.
An overview reference of currently available liposuction technology is contained in Illouz Y G: History and current concepts of lipoplasty, Clinics in Plastic Surgery 23(4): 721-730, 1996.
Prior art patents disclosing prior devices include bipolar electrode probe devices for use in electro-cautery and electro-coagulation. One patent relating to an Electro-Surgical Instrument is U.S. Pat. No. 2,275,167 issued to Bierman. This patent describes an electro-surgical device which is designed to coagulate or ablate tissue in order to destroy tissue. A suction cup shaped cavity is produced to draw the tissue into the electrode area of the device. The device is not configured to provide a conduit for removal of the tissue through the device.
A Combined Electro-Coagulator-Suction Instrument is disclosed in U.S. Pat. No. 3,828,780, issued to Morrison. This patent defines an instrument with a non-insulated tip which is connected electrically to a source of electrical current through a second channel separate from the channel for applying suction. The combined instrument has a source of current which is exposed on the external surface of the device, is oriented at the distal end of the device coaxially with the suction and does not provide a source of irrigation. It is believed that the Morrison device would be unsuitable for use in lipectomy surgery and in fact is intended not for removal of tissue but for aspiration of blood to allow proper action of the coagulation to obtain hemostasis.
A Suction Surgical Instrument is disclosed in U.S. Pat. No. 3,902,494 issued to Haberlen. This patent describes a device with a monopolar electrode which is, in the preferred embodiment, ring shaped on the external surface of the tip of the device in communication with a suction channel. There appears to be an external application of current. The device appears to be monopolar and not bipolar and there is no apparent provision for irrigation.
An example of a Co-axial Bipolar Probe is illustrated by U.S. Pat. No. 4,674,499 issued to Pao. This patent describes a bipolar electrode probe device for use in electro-cautery and electro-coagulation having a central electrode which is described as protrusive beyond the insulating sheath. The device has a single channel which may be used for irrigation or alternatively placed under vacuum. Thus, a single lumen does not appear to provide for the simultaneous application of fluid irrigation and vacuum. Also, the lumen appears to be centrally positioned and the spacing of the distance between the electrodes, about 0.2 to about 0.45 mm, is believed substantially smaller than needed for utilization in suction assisted lipectomy.
An Electro-Surgical Device with Suction and Irrigation is disclosed in U.S. Pat. No. 5,195,959, issued to Smith. The Electro-Surgical Device described therein includes a means of providing mono-polar electro-cautery current in combination with the ability to produce suction of fluid or blood in the field and irrigation introduced into the surgical field. The orientation and configuration of the device appears to apply irrigation or electrical current to the surgical field itself.
A device and a method of Using a Multi Modality Probe With Extendable Bipolar Electrodes is disclosed in U.S. Pat. Nos. 5,401,272 and 5,441,498 issued to Perkins. The method described appears to employ a device which may have suction, electrical source, an irrigation source and a laser source. The device appears to be designed for cutting and then coagulating tissue. The electrodes of the device are movable extending to the exterior of the device.
Thus, there is a need for devices and methods for performing suction assisted lipectomies which, due to the coagulation effect of the electrocautery, accomplishes faster and more complete fat removal; obtains better hemostasis, produces less bruising, less blood loss and faster patient recovery; costs less than ultrasonic or laser liposuction cannulas; when the device is manufactured as a disposable device, given the difficulty of cleaning and sterilizing hollow instruments, reduces infection risks and uses bipolar electrocautery to minimize the risk of spark gap injury, skin burns or other complications from overexposure or unintended tissue exposure to electrical energy.